#ifndef _HINT_H
#define _HINT_H
/*
 * This file is distributed as part of MaxScale.  It is free
 * software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation,
 * version 2.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Copyright SkySQL Ab 2014
 */

/**
 * @file hint.h The generic hint data that may be attached to buffers
 *
 * @verbatim
 * Revision History
 *
 * Date		Who		Description
 * 10/07/14	Mark Riddoch	Initial implementation
 *
 * @endverbatim
 */

#include <skygw_debug.h>


/**
 * The types of hint that are supported by the generic hinting mechanism.
 */
typedef enum {
	HINT_ROUTE_TO_MASTER = 1,
	HINT_ROUTE_TO_SLAVE,
	HINT_ROUTE_TO_NAMED_SERVER,
	HINT_ROUTE_TO_UPTODATE_SERVER,
        HINT_ROUTE_TO_ALL, /*< not implemented yet */
	HINT_PARAMETER
} HINT_TYPE;

/**
 * A generic hint.
 *
 * A hint has a type associated with it and may optionally have hint
 * specific data.
 * Multiple hints may be attached to a single buffer.
 */
typedef struct hint {
	HINT_TYPE	type;	/*< The Type of hint */
	void		*data;	/*< Type specific data */
	void		*value;	/*< Parameter value for hint */
	unsigned int	dsize;	/*< Size of the hint data */
	struct hint	*next;	/*< Another hint for this buffer */
} HINT;

extern	HINT	*hint_alloc(HINT_TYPE, void *, unsigned int);
extern	HINT	*hint_create_parameter(HINT *, char *, char *);
extern	HINT	*hint_create_route(HINT *, HINT_TYPE, char *);
extern	void	hint_free(HINT *);
extern	HINT	*hint_dup(HINT *);
bool            hint_exists(HINT **, HINT_TYPE);
#endif
